Elevation of catecholamines are known to occur in stressful situations like hypoglycemia or diabetic ketoacidosis. This study is designed to measure the relative contributions of hepatic glycogenolysis and gluconeogenesis to glucose production when plasma epinephrine in increased. 13C-nuclear magnetic resonance spectroscopy (natural-abundance 13C) will be used to measure rates of whole body glucose production. This study will be performed in healthy subjects and poorly controlled type I diabetic subjects.